AU2010297385B2

AU2010297385B2 - Method for producing fresh milk having a longer shelf life

Info

Publication number: AU2010297385B2
Application number: AU2010297385A
Authority: AU
Inventors: Egon Baumeister; Michael Meyer; Heinrich Winkenhoff
Original assignee: GEA Mechanical Equipment GmbH
Current assignee: GEA Mechanical Equipment GmbH
Priority date: 2009-09-16
Filing date: 2010-09-15
Publication date: 2014-06-19
Anticipated expiration: 2030-09-15
Also published as: EP2477502B2; EP2477502B1; US10285412B2; US20120183658A1; JP2013504335A; WO2011032957A1; DE102010037550A1; EP2477502A1; US20140272043A1; JP2016027821A; AU2010297385A1; CN102469802A

Abstract

The invention relates to a method for producing fresh milk having a longer shelf life, having a shelf life of at least 20 days, wherein a at least two-stage centrifugal germ removal is performed, in particular for removing spore-forming bacteria relevant to spoilage. The method also allows a subsequent integration of the germ removal stages into a conventional system for milk pasteurization.

Description

WO 2011/032957 PCT/EP2010/063511 Method for producing fresh milk having a longer shelf life The invention relates to a method for producing fresh 5 milk having a longer shelf life. In a general method for producing drinking milk (fig. 1), raw milk is first heated to a preset skimming temperature. This can be, for example, between 55 and 10 62 0 C, in order to prevent protein damage. After the skimming, that is to say separating the raw milk into cream and skimmed milk, the cream is homogenized. 15 Then the skimmed milk is optionally standardized by adding a predetermined amount of homogenized cream. Hereafter, the standardized and homogenized milk must 20 be pasteurized at a temperature between 72*C and 75*C and for a treatment time of 15 seconds to 30 seconds. In this step, spoilage-relevant germs are killed. Finally, the milk is cooled to a temperature of 6-70C. 25 Such a method of production, with aseptic packaging, ensures a shelf life of up to 12 days. In addition, a great variety of methods are known which ensure an extended shelf life of milk. Usually, high 30 temperature heat-treated milk, however, exhibits significant taste differences compared with fresh milk. For instance, what is termed extended shelf life (ESL) milk is known which has a shelf life of at least 35 20 days at storage temperatures T 80C. 3020435_1 (GHMatters) P89077.AU WO 2011/032957 - 2 - PCT/EP2010/063511 An important precondition for a longer shelf life of milk is a great germ reduction of spore formers and a reduction of the total germ count. These accelerate the spoilage of milk to a great extent. 5 Known methods which are used in the production of ESL milk are described in more detail hereinafter: ESL direct heating system 10 As starting product, standardized and thermally treated milk or only fat-standardized milk is provided in a store. 15 In the direct heating system, the product is regeneratively heated to 700C to 85 0 C and then heated to a maximum of 127*C by direct steam injection. After hot-holding the milk for 3 seconds, it is cooled in a flash cooler to 70 0 C to 85 0 C. Aseptic homogenization at 20 70 0 C then follows. ESL indirect heating system As starting product, the same product as in the direct 25 heating is provided in a store. The milk is regeneratively heated to 700C and then septically homogenized. The product is then heated to 1050C to 107*C in the regenerative heat exchanger and heated in the heater section to 127C for 2 seconds. 30 ESL microfiltration The raw milk here is separated at the usual skimming temperature of 550C. The skimmed milk is then micro 35 filtered likewise at 55C. The cream can be heated with the retentate in the course of 6 seconds to 105 0 C to 30204351 (GHMater) P89077.AU WO 2011/032957 - 3 - PCT/EP2010/063511 125 0 C and mixed with the skimmed milk and homogenized. The milk is then pasteurized and cooled to 4 0 C to 60C. Membranes having pore sizes of 0.8 pm to 1.4 pm are 5 used which are said to guarantee a germ retention greater than 99.5%. This produces a low-germ permeate and a high-germ retentate. The germ concentrate (retentate) can be concentrated and after a high temperature heat treatment can be recirculated to the 10 permeate. ESL deep-bed filtration In this method, filter candles made of polypropylene 15 are used. The pore size of the prefilter is 0.3 pm and that of the main filter 0.2 pm. The filtration proceeds at separation temperature and the germs are separated in the depth of the filter without forming retentate. The method sequence of the heating system corresponds 20 to that of the microfiltration. The product of the method presented is organoleptically comparable with conventionally pasteurized milk. The removal of germs from milk by microfiltration for the 25 purpose of extending shelf life has proved in principle to be particularly suitable. DE 100 36 085 C1 discloses a method for removing germs from milk, in particular in production of milk for 30 cheese making. For removing germs from milk, the milk is separated into skimmed milk and cream in a separator. Then germs are removed from the skimmed milk by microfiltration or a separator. 35 US 3 525 629 A discloses a method for sterilizing milk for cheese making. In this method, a bacteria 3020435_1 (GHMatters) P89077.A) containing milk slurry is separated off from the milk in a two-step centrifugal method, sterilized, and recirculated to the milk circuit. Such a milk, however, cannot be termed fresh milk. 5 A two-step centrifugal germ removal is also disclosed in the article "Neuer Stern in der Milchstrasse" [New star in the milky way] by Iloi Wasen, Deutsche Molkerei Zeitung, 2003, pp. 40/41. However, specific method 10 sequences are not disclosed in the article. The document "Separatoren ftir Milch-Reinigung und Milch-Entkeimung" [Separators for milk purification and removal of germs from milk] by Hanno R. Lehmann and 15 Ernst Dolle as scientific document No. 12 Westfalia Separator AG, Oelde, 1st edition, 1986, figure 20 and chapter 3.1.2 discloses two-step removal of germs from skimmed milk. This has the disadvantage that the cream fraction either has a high fraction of spores or, on 20 account of heating, only has a low fraction of O-lacto globulin. It is the object of the invention, proceeding from the previous prior art, to provide an alternative method 25 for producing fresh milk having a longer shelf life, wherein variants of the invention are also to be provided in which no high-temperature heat treatment of the milk or of milk components is obligatorily necessary. 30 In view of the above object, the present invention provides a method for producing fresh milk having a longer shelf life, wherein at least two stages of 5410206_1 (GHMatters) P89077.AU - 4a centrifugal germ removal are carried out and each stage of centrifugal germ removal is carried out either a) from raw milk before a standardization; or b) from whole milk after a standardization. 5 Expressed another way, the present invention provides a method for producing fresh milk having a longer shelf life, in which an at least two-step centrifugal germ removal (900, 901) 10 a) from raw milk before a standardization or b) from whole milk after a standardization is carried out. The present invention also provides a method for 15 producing fresh milk having a longer shelf life, wherein at least two stages of centrifugal germ removal are carried out, and wherein at least one germ removal stage already proceeds before a skimming, and a second germ removal stage proceeds during processing of 20 skimmed milk. Expressed another way, the present invention provides a method for producing fresh milk having a longer shelf life, in which an at least two-step centrifugal germ 25 removal (900, 901) is carried out, wherein at least one germ removal stage already proceeds before a skimming, whereas a second germ removal stage proceeds during processing of skimmed milk. 30 In this case, advantageously, germs are also removed from the cream contained in the fresh milk once, or, particularly advantageously, twice. 5410206_1 (GHMatters) P89077.AU WO 2011/032967 - 5 - PCT/EP2010/063511 Advantageous embodiments of the invention are present in the subclaims. 5 By using an at least two-step centrifugal removal of germs, generally it is possible to dispense with not only a filtration but also a heating to temperatures of about 125*C of the raw milk before separation or of the drinking milk after standardization. 10 The at least two-step centrifugal removal of germs effects a high germ reduction of spoilage-relevant spore formers. For instance, in one liter of milk after the two-step centrifugal germ reduction, at most 1 Bacillus cereus spore per 10 ml of liquid from which 15 germs have been removed, or fewer of these spores, is detectable. Precisely this aerobic spore former increases a hundred fold in a period of 6 days and impairs to a great extent the shelf life of the milk owing to sweet curdling. In this manner, a milk having 20 a longer shelf life is provided which has a shelf life at a storage temperature T 8 0 C in any case up to 21 days and in which it is no longer necessary to add high-temperature heat-treated material in the production. Although an extreme shelf life of 40 days 25 or more is not necessarily achieved, compared with conventional fresh milk, the markedly increased shelf life period of a minimum of 20 days or more provides a milk having extended shelf life which is not subject to any flavor impairments owing to high-temperature heat 30 treatment. Even the cream does not need to be high temperature heat treated, but can be if desired. The lactulose content achieved in the fresh milk having an extended shelf life produced according to the 35 invention and the content of P-lactoglobulin are comparable with the corresponding contents in fresh 302043_1 (GHMatters) P89077.AU WO 2011/032957 - 6 - PCT/EP2010/063511 milk. The minimization of germ-rich concentrate which is removed via the discontinuous emptyings of the 5 separator drum is preferably achieved by using a PRO+ system, that is to say a system of the type of EP1786565 having fin bodies which are arranged radially outside a disk package of a separator. By this is meant that it is possible to discharge very small amounts of 10 concentrate arising in a very large emptying interval. The at least two-stage centrifugal germ removal can, in addition to the step of skimming, be integrated at various sites into a method for preserving fresh milk. 15 The germ removal steps need not follow one another in this case. By an additional separation of solids off from the milk during the skimming, likewise a certain discharge of 20 germs from the milk can be effected already. The skimming step, however, is in this context, only to be considered as a type of preliminary germ removal, but not as a complete germ removal step. 25 Germ removal in this context means the targeted treatment of milk or skimmed milk for clarifying from solids, such as germs, spores, bacteria and the like, preferably using a separator, in particular a disk separator. 30 In this germ removal the liquid phase (the influent milk) is clarified from solids centrifugally. It is also conceivable - but not absolutely necessary - to recirculate a substream of the liquid that is clarified 35 in this manner to the feed of the germ removal separator, in order optionally to further optimize the 3020435_1 (GHMaters) P89077.AU WO 2011/032957 - 7 - PCT/EP2010/063511 germ removal effect. By integrating an at least two-step centrifugal germ removal into the abovementioned general production 5 method, an advantageous extension of the shelf life of the milk to a minimum of 20 days can generally be achieved. It is advantageous when the at least two germ removal 10 steps are already carried out successively before the skimming, such that the number of the aerobic germ farmers in question has already been drastically lowered before the various heating processes of the following process steps, preferably to a value below 15 the limit of detection. In a further embodiment variant, at least one germ removal step can proceed already before the skimming, whereas a second germ removal step is integrated into 20 the method during processing of the skimmed milk. In a further embodiment variant, germs can be removed from the whole milk in two successive centrifugal steps after standardization, that is to say after feeding an 25 amount of cream to the skimmed milk. Whereas the first centrifugal germ removal lowers the number of the corresponding aerobic spore formers by up to 90%, in the later course a separate germ removal 30 from the skimmed milk can proceed in a further centrifugal germ removal step. To ensure freedom from germs, in this embodiment variant, it is advantageous if, after the separation 35 step of skimming, the cream is briefly heated to a temperature, preferably between 100 and 1400C, in order 3020435_1 (GHMatlers) P89077AU WO 2011/032957 - 8 - PCT/EP2010/063511 not only to ensure freedom of the cream from germs; but also of the skimmed milk after remixing. Since freedom of the cream from germs proves to be 5 advantageous in the storage of excess cream, the cream can be heated briefly immediately after the skimming and before the quantitative division, such that germs are also removed from the excess cream. 10 To ensure freedom from germs during storage of the fresh milk having a longer shelf life, an aseptic packaging that is known per se is advantageous. Hereinafter the invention will be described in more 15 detail with reference to a plurality of working examples, with reference to the drawings. In the drawings: 20 fig. 1 shows a schematic sequence of a method for producing fresh milk; fig. 2 shows a schematic sequence of a first embodiment variant according to the 25 invention of a method for producing fresh milk having a longer shelf life; fig. 3 shows a simplified circuit diagram of an arrangement for operating the first 30 embodiment variant according to the invention; figs. 4a, 4b show schematic sequences of two embodiment variants according to the 35 invention of a method for producing fresh milk having a longer shelf life; 3020435_1 (GHMatters) P89077.AU WO 2011/032957 - 9 - P T/EP2010/063511 fig. 5 shows a simplified circuit diagram of an arrangement for operating the second embodiment variant according to the 5 invention; Fig. 1 shows a flow chart/block diagram which reflects a known production process for "traditionally produced fresh milk". 10 Stored raw milk 100 in this case, at a temperature of 2-80C is warmed or warmed up using a plate heat exchanger in step 200 to a skimming temperature of 50-600C, preferably 550C. Then the raw milk is 15 centrifugally separated in a separator into cream 310 and skimmed milk 360 in step 300, or the milk is skimmed. The cream 310 is then, according to the desired cream content of the milk, divided in step 320, where excess cream (step 340) can likewise be stored 20 (step 350) if desired. Then, the cream is homogenized in step 330, in such a manner that a breakdown of fat balls for stability against creaming results. The skimmed milk (step 360) is then mixed with the 25 desired amount of cream, standardized, and in step 400 warmed or short-time heated to a temperature of 70-800C, preferably 740C, by way of a plate heat exchanger, and in step 500 kept hot for a correspondingly long time. At this temperature, 30 spoilage-relevant microorganisms are to be destroyed and unwanted enzymes inactivated. For reduction of germ growth, the milk is then cooled preferably using a plate heat exchanger, step 600, down 35 to 4-60C, preferably 5 0 C, for storage (step 700). Aseptic packaging of the milk, step 800, in bottles or 3020435_1 (GHMatters) P89077.AU WO 2011/0329 7 - 10 - PCT/EP2010/663511 in aseptic drinking cartons and consumption of the packaged milk is generally possible in the course of 12 days. 5 Fig. 2 is a block diagram in which, in addition to the previously known steps, two germ reduction steps, 900, 901, are added. These two germ reduction steps are integrated into the process before the skimming, or before skimming of the raw milk (step 300). 10 In this case, after heating to a separation temperature of 50-600C, preferably 550C, step 200, the raw milk is freed from bacteria and spores in two germ-removal steps 900 and 901. Already before the skimming step, a 15 germ removal, or removal of germs from the milk is thereby carried out at preferably 55 0 C. Therefore, on skimming, not only is substantially spore-free cream (step 310) but also germ-free skimmed 20 milk (step 360) are thereby obtained, wherein the cream in the later course can be added back to the skimmed milk for standardization. Pasteurization of the drinking milk after standardization can proceed in this case at 74-850C, preferably 800C, such that remaining 25 spoilage-relevant microorganisms and unwanted enzymes can be correspondingly destroyed or inactivated in this case. Fig. 3 shows the circuit diagram of a plant which is 30 operated according to the schematic shown in fig. 2. In this case raw milk passes via a feed Z into a storage tank 1 in which the raw milk is stored at preferably 4-60C. From the storage tank, the raw milk is passed via subsection 2a of a countercurrent-flow plate heat 35 exchanger 2, where the raw milk is warmed to a temperature of 50-600C, preferably 550C. 30204351 (GHMatters) Pa9077.AU WO 2011/032957 - 11 - PCT/EP2010/063511 The raw milk is then transferred at this temperature into a first germ-removal separator 3. In this step, there is a coarse germ removal from the milk, wherein 5 the number of spoilage-relevant spore formers can be reduced by about 90%. After the coarse germ removal, the raw milk is transferred into a second germ removal separator 4. In 10 this second germ removal step, germs are reliably cleared in such a manner that at least Bacillus cereus spores are no longer detectable. The raw milk from which germs have been removed is then 15 skimmed by a skimming separator 5 in which the raw milk is separated into cream and skimmed milk. The cream leaves the skimming separator 5 via the line 8 and can be kept at preferably 740C by the heat 20 exchanger 9 in this case. Alternatively, the heat exchanger 9 can heat the cream to a temperature of 110 140 0 C, preferably 1250C, in order in this manner to connect an additional thermal post-removal of germs. Optionally, also, cleaning-in-process (CIP) of the 25 plant can proceed via a separate feed line. By way of a valve which is not shown, a quantitative division of the cream proceeds, wherein some of the cream can be removed from the process as excess cream E 30 and stored. Alternatively, further additional cream can be fed to the process. After the amount of cream is set to a predetermined value, the cream is passed into a homogenizer 11. The cream is then recirculated to the skimmed milk via a valve which is not shown. 35 This process, also termed standardization, takes place 3020435_1 (GHMatters) P89077 AU WO 2011/032957 - 12 - PCT/EP2010/063511 in a connection piece which is not shown as a connection of the skimmed milk line to the cream line. The standardized fresh milk is then fed via a line to 5 the plate heat exchanger 2 where it is warmed up on passage from preferably 55 0 C (section 2b) to preferably 74 0 C (section 2c) . For heating the milk, in the present example steam D is used, which introduces the required heat input in countercurrent by condensation. The milk, 10 for hot holding, is then passed via a further heat exchanger 7. The heating to preferably 74 0 C introduces a mild inactivation of spore formers. The standardized fresh milk (T = approximately 74 0 C) is 15 then in section 2c of the plate heat exchanger and there via the section 2b (Tmilk = approximately 55 0 C) , section 2a (Tmilk = approximately 8 0 C) and section 2d (Tmiilk = approximately 4 0 C) cooled down to a temperature of 4-6 0 C. Section 2d can be designed as ice cooling 20 using a coolant feed CF and a coolant outlet CO. Via an outlet A, the fresh milk that now has a longer shelf life is passed onto an aseptic packaging system. Corresponding measurement and control devices for the parameters (pressure, germ count, cell count, 25 temperature, motor power of the separators, etc.) have not been shown in the present circuit plan for the sake of clarity. In fig. 4, the two germ-removal steps 900, 901 at 30 various sites of the process sequence are integrated therein. Whereas the first germ removal 900 proceeds before the skimming 300 or the separation of the raw milk into cream (step 310) and skimmed milk.(step 360), the germ-removal step 901 serves for .removing germs 35 from skimmed milk (step 360). The cream that is separated off, subsequently to the skimming step, is 3020435.1 (GHMatters) P89077.AU WO 2011/032957 - 13 - PCT/EP2010/063511 additionally heated to preferably 125oC in order to ensure in this manner freedom of the cream from germs. After the excess cream (step 340) has been separated 5 off (step 320), a predetermined amount of cream is fed to the germ-free skimmed milk 360. Then, the drinking milk is again warmed up (step 400) in order to inactivate any remaining spoilage-relevant microorganisms or enzymes. A hot holding step 500 then 10 follows and also a cooling process (step 600), in such a manner that the resultant drinking milk can be stored and packaged at a temperature of preferably 50C or below. 15 In the example of fig. 4a, therefore, a first germ removal from the raw milk proceeds before the separation and a second germ removal from the skimmed milk after the separation of cream and skimmed milk. Therefore, germs are removed separately from both 20 components of fresh milk, cream and skimmed milk, in this process. Alternatively, it is also conceivable not to give the homogenized cream a high-temperature heat treatment but 25 to pass it, after the homogenization, back into the skimmed milk for standardization and then to subject this mixture of skimmed milk and cream together to a second germ removal 901. This can then be followed again by the steps 400 to 800 for final processing of 30 the packaged fresh milk (see fig. 4b). Fig. 5 shows the circuit diagram of a system which is operated according to the schematic shown in fig. 4a. In this case the raw milk, analogously to figure 3, is 35 warmed to 55 0 C in a plate heat exchanger 2' and then subjected to coarse germ removal in a germ removal 3020435_i (GHMatters) P89077 AU WO 011/032957 - 14 - PdT/EP2010/063511 separator 3'. In contrast to the working example of fig. 3, the raw milk from which germs have been removed is skimmed by a 5 skimming separator 5' already after the first germ removal step. After skimming, the skimmed milk is passed into a second germ removal separator 4' where the skimmed milk 10 is again subjected to germ removal, separately from the cream. The remaining process steps are achieved in a manner similar to fig. 3 in terms of apparatus. 15 Compared with the methods of treatment in the pasteurization of "traditionally produced fresh milk", in the production of fresh milk having a longer shelf life, greater demands are made of the quality of the 20 raw milk, the processing, with respect to purity, and of storage, with respect to cooling. For instance, for packaging, primarily aseptic packaging comes into consideration. The raw milk should be of the highest quality and generally not older than 48 hours. 25 Alternatively to the three embodiment variants shown, a two-step centrifugal germ removal after standardization of the milk is likewise possible according to the invention. For this purpose, for example as skimming 30 separator, the applicant's model MSE 230-01-777 comes into consideration, and as germ-removal separators, the model CND-215-01-076 (additionally converted to a PRO+ system, as described in E1786565) and the model CSE 230-01-777 come into consideration. As germ-removal and 35 skimming separators, continuously operating self emptying disk separators are preferably utilized. 3020435_1 (GHMatters) P89077 AU WO 2011/0312957 - 15 - PCT/EP2010/063511 In this process a previously conventional Pasteur system can be retrofitted without problems with two additional germ-removal separators and corresponding 5 heating and cooling devices for cream. The phase of bacteria and possibly a fraction of milk removed in the method is subsequently preferably discarded. Sterilization of this phase by heating, that 10 is to say destroying the bacteria and recirculation of such a sterilized phase to the fresh milk from which germs have been removed is not preferred since this adversely affects the quality of the fresh milk, in particular the content thereof of D-lactoglobulin and 15 lactulose. P-Lactoglobulin is a whey protein which occurs in cow's milk. A high content of f-lactoglobulin is an indicator of high milk quality. In the heating of the milk, 20 denaturation of the milk protein occurs and consequently a lower content of whey proteins, and so also of P-lactoglobulin. Lactulose is a byproduct of a rearrangement reaction of 25 lactose which proceeds on heat treatment. Lactulose acts as a laxative and cannot be used by the human body. Lactulose is not present in raw milk. Therefore, a low lactulose content is an indicator of freshness and quality of the milk. 30 Hereinafter, some guide values are listed for lactulose content and f-lactoglobulin content from the directive 92/46/EEC of the Council of the European Community. In addition, a proposal of the German Federal Ministry for 35 Nutrition and Food (BFEL) for the P-lactoglobulin content in various processed milk varieties is given. 3020435_1 (GHMa81ers) P89077.AU WO 2011/032957 - 16 - PCT/EP2010/0635111 Product EU proposal Proposal of the BFEL (92/46/EEC) Sterilized lower limit > 600 mg lactulose/l milk lower limit < 50 mg O-lactoglobulin/l upper limit < 1200 mg lactulose/l UHT milk lower limit > 100 mg lactulose/l upper limit < 50 mg $-lactoglobulin/l > 400 mg lactulose/l lower limit Peroxidase negative Peroxidase negative High temperature upper limit < 50 mg lactulose/l > 2000 mg $-lactoglobulin/l heat- upper limit > 2000 mg O-lactoglobulin/l treated lower limit Phosphatase negative Phosphatase negative milk Pasteurized upper limit Peroxidase positive Peroxidase positive milk upper limit Lactulose not detectable upper limit > 2600 mg O-lactoglobulin/l > 3000 mg $-lactoglobulin/l In the table listed above, sterilized milk, ultraheat treated milk (UHT), high-temperature heat-treated milk 5 and pasteurized milk are compared and guide values for the individual varieties are stated in order to enable a definition of individual milk varieties and to avoid the risk of confusion on the part of the consumer. In this case a pasteurized milk may be made equivalent to 10 a traditionally produced fresh milk, wherein the processing method is shown in fig. 1. Hereinafter, individual measured values of a pasteurized milk from raw milk from which germs are 15 removed and which was treated according to an embodiment variant of the method according to fig. 2 are compared with the measured values of a microfiltered milk or direct-heated milk. 20 In this case the classification of a pasteurized milk 30204351 (GHMatters) P89077.AU WO 2011/032957 - 17 - PCT/EP2010/063511 is guided by the guide values stated in the table above for lactulose and D-lactoglobulin. Product Values Category Pasteurized milk made 3810 mg/i $-lacto- Pasteurized milk from raw milk from globulin which germs were 5 mg/l lactulose removed ESL milk produced by 3980 mg/l P-lacto- Still pasteurized filtration globulin milk 9 mg/l lactulose ESL milk produced by 1490 mg/l P-lacto- High-temperature direct heating globulin heat-treated milk 26 mg/l lactulose 5 As can be seen from the measured values, the pasteurized milk produced from raw milk from which germs were removed is equivalent in quality to pasteurized milk, or traditionally produced fresh milk. 3020435_1 (GHMatters) P89077.AU WO 2011/032957 - 18 - PCT/EP2010/063511 Reference Skimmed milk line 6, 6', 6" numbers: Storage tank 1, 1', 1" Cream line 8, 8', 8" (reservoir) Germ-removal 3, 3' 3" separator Skimming 5, 5', 5" separator Heat exchanger 7, 7', 7" Heat exchanger 9, 9', 9" Homogenizer 11, 11', 11" Fresh milk line 13, 13', 11" Skimmed milk 360 Heating (cream) 370 Hot holding (cream) 380 Storage raw milk 100 Short-term 400 heating/pasteurization Warming 200 Hot holding 500 Skimming 300 Cooling 600 Cream 310 Storage 700 Subdivision 320 Heating/cooling liquid Homogenizing 330 feed and outlet Fl (cream) Excess cream 340 Separation germ removal I 900 Separation germ removal II 901 Plate heat 2, 2', 2" Steam D exchanger Germ-removal 4, 4', 4" separator Storage (excess 350 Coolant outlet CO cream) Packaging 800 Cleaning CIP Feed (raw milk) Z Outlet (fresh A milk) Outlet for E excess cream Coolant feed CF 3020435_1 (GHMatters) P89077AU - 18a It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in 5 Australia or any other country. 5410206_1 (GHMatters) P89077.AU

Claims

1. A method for producing fresh milk having a longer shelf life, wherein at least two stages of 5 centrifugal germ removal are carried out and each stage of centrifugal germ removal is carried out either a) from raw milk before a standardization; or b) from whole milk after a standardization. 10

2. A method for producing fresh milk having a longer shelf life, wherein at least two stages of centrifugal germ removal are carried out, and wherein at least one germ removal stage proceeds 15 before a skimming, and a second germ removal stage proceeds during processing of skimmed milk.

3. The method as claimed in claim 1, wherein after the at least two stages of centrifugal germ 20 removal, the milk is heated.

4. The method as claimed in claim 3, wherein the heating is carried out regeneratively at 70-85 0 C. 25

5. The method as claimed in any one of the preceding claims, wherein the method has the following steps: a) heating of raw milk to a predetermined skimming 30 temperature; b) skimming the raw milk i. dividing the amount of cream on the basis 35 of predetermined guide values; 5410206_1 (GHMatters) P89077.AU - 20 c) standardizing the milk; d) heating the standardized milk; 5 e) hot-holding the milk; f) cooling the milk; and g) packaging. 10

6. The method as claimed in any one of the preceding claims, wherein at least one stage of centrifugal germ removal is carried out after standardizing the milk and before packaging. 15

7. The method as claimed in any one of the preceding claims, wherein at least one stage of centrifugal germ removal proceeds after heating of raw milk and before skimming and at least one further stage 20 of centrifugal germ removal is carried out from the skimmed milk.

8. The method as claimed in claim 7, wherein cream is heated for germ removal after skimming the raw 25 milk.

9. The method as claimed in any one of the preceding claims, wherein cream is heated for germ removal after skimming raw milk and before dividing the 30 amount of cream.

10. The method as claimed in any one of claims 5 to 9, wherein the packaging is carried out as aseptic packaging. 5410206_1 (GHMatters) P89077.AU - 21

11. The method as claimed in any one of the preceding claims, wherein at least one stage of the centrifugal germ removal is carried out in a separator having a disk stack made of separation 5 disks.

12. The method as claimed in any one of the preceding claims, wherein a separator with fins is used which are arranged radially outside the separation 10 disks in the drum of the separator.

13. The method as claimed in any one of the preceding claims, wherein a sterilized phase is not recirculated into a fresh milk from which germs 15 have been removed.

14. A method for producing fresh milk having a longer shelf life, substantially as herein described with reference to the Figures. 20

15. A fresh milk having a longer shelf life prepared by the method of any one of claims 1 to 14. 5410206_1 (GHMatters) P89077.AU